(1) Field of the Invention
The invention relates to an apparatus and method for washing undesirable matter off of tubular conduits as they are withdrawn during a trip out from within a subterranean well.
(2) Brief Description of the Prior Art
Subterranean wells are commonly drilled and worked over for the purpose of recovering water or hydrocarbon constituents, such as oil and gas. These wells may be found on land or upon platforms or drill ships on the oceans and seas through the world. For example, FIGS. 1A and 1B illustrate a typical inland rotary drilling rig and its components. A subterranean well W is shown with set casing C secured in place by cement column C-1. A conduit string CS is shown inserted within the well W and interior of the casing C. The conduit string CS is formed by a number of tubular conduits TC which are threaded one to another at each end at respective collars or upset portions TCC. Drill collars DC are secured along the tubular conduits TC with a drill bit DB at the lowermost end of the conduit string CS. A conductor pipe CP extends within the uppermost portion of the well W to a casinghead CH in a cellar CHC at the top surface of the well W. A stack of ram blowout preventers RBOP is placed on the casinghead and an annular blowout preventer ABOP is secured to the top of the ram blowout preventers RBOP. The conduit string CS is inserted into and withdrawn from the well W through the blowout preventers RBOP and ABOP and through a kelly bushing KB and rotary table RT extending through an opening RTO in the rig floor RF. A Kelley K extending from a swivel S suspended from a traveling block TB enables the conduit string CS to be inserted and removed during tripping into or out of the well W. The conduit string CS is made up at the rig floor RF by roughnecks RN manipulating power tongs PT to secure or remove one tubular conduit TC to or from another tubular conduit TC during make up or disassembly of the conduit string CS.
As the conduit string CS is withdrawn from the well W during a trip out, the exterior of each tubular conduit TC will have considerable undesirable matter upon such exterior. This “undesirable matter” may include both liquids and solids, such as aqueous and oil based or emulsion drilling or workover fluids, barite, bentonite, polymers, well cuttings, acidic or basic corrosion inhibitors, flocculants, dispersants, shale, and other materials commonly found within the well as the result of the drilling or workover operation. Even though the roughnecks may wear special gloves and clothing, it is not at all unusual for these personnel to get a considerable amount of this undesirable matter upon their clothing, and even on their skin, in their eyes, and such, during the tripping operation. If the undesirable matter is acidic, it can cause a burning sensation upon contact with human skin. Moreover, especially on offshore wells, this undesirable matter constitutes an environmental hazard if it is not properly and immediately collected and carefully disposed of, to avoid dumping into the ocean or other environmentally sensitive area.
The present invention addresses the concerns as above described.